Naked Science Forum

Non Life Sciences => Geek Speak => Topic started by: syhprum on 02/02/2019 18:49:20

Title: What software does the BBC use to transmit video over the Internet?
Post by: syhprum on 02/02/2019 18:49:20

Some broadcast via the internet are abysmally poor quality while others are excellent apparently set up by professionals.
There are numerous software's available for these links I was wondering which ones are favoured by the broadcasters. 

Title: Re: What software does the BBC use to transmit video over the Internet?
Post by: RD on 02/02/2019 21:21:54

Quote from: syhprum on 02/02/2019 18:49:20

Some broadcast via the internet are abysmally poor quality while others are excellent ...

There can be user-adjustable quality-setting in online video players : trading-off resolution against bandwidth.
Sometimes the quality setting can change automatically depending on your internet-connection. (https://support.google.com/youtube/answer/91449?hl=en-GB)

Title: Re: What software does the BBC use to transmit video over the Internet?
Post by: evan_au on 02/02/2019 22:09:46

Video quality is affected by the loss of data packets from the video stream, causing pixellation (blocky picture), pauses, misalignment of moving images and jumpy motion.
- This "Frame Loss Ratio" (FLR) is higher at times of peak data usage - typically around 7pm in residential areas (increasing from 4pm, declining after 10pm).
- FLR also can occur for reasons related to corrosion in your own home wiring, your microwave interfering with your WiFi signals, or activity of your neighbour's WiFi connection. Optical fiber connections are the best because they are immune to this type of interference.
- FLR can also occur because some device like a smartphone or a computer suddenly decides for itself that it is going to download a software update that may be 1 Gigabyte in size

Early types of video broadcasting on the internet just sent the packets at an encoding rate that was set for a particular show
- The rate varies with the content - rapid motion requires a much higher data rate than a static image. These peaks could exceed the capacity of your internet service, causing FLR during rapid motion of the image.
- There was no checking that your line is able to cope with these peak rates
- In contrast, Netflix and other more recent video services have been smarter
       - If frames are lost, they retransmit them (effectively no FLR)
       - they check the capacity of your line on an ongoing basis, and at times of congestion will reduce the data rate on your line. This makes the picture a bit more "blocky" for a few seconds, but this is less noticeable than the show stopping entirely

Most video services don't deliver the video themselves, but contract to a "Content Delivery Network" (CDN) to deliver the video.
- Akamai is one of the largest CDNs, but is almost unknown to the general public, despite the fact that the public use it every day.
- Amazon is also large, but only known because of their online store, not for CDN services

https://en.wikipedia.org/wiki/Content_delivery_network

Title: Re: What software does the BBC use to transmit video over the Internet?
Post by: syhprum on 02/02/2019 23:44:05

I am experimenting with BlueStacks that enables me to emulate a Galaxy device on a PC, I was wondering which video internet program to use, I have just about got the hang of Skype but there are about half a dozen others recommended.
I wonder how compatable they are with each other.
I have a good fibre optic service from Virgin 100 Mb/s.